Bistable relay arrangements of this type are already known from the French patent N.degree. 1,527,178. In this known arrangement, the yoke, the core and the armature of each relay device form a magnetic circuit which is independent of that of the other device. The interaction means are of complex structural mechanical nature and comprise a fork fastened onto the yokes made as one single piece and onto which is pivotally connected a ring bow urged towards the coils by resilient and flexible rods hooked thereto. The ring bow is positioned to bear upon two cams mounted straddlewise onto the upper edge of two armature blades with one cam exhibiting a shape permitting an unhooking from the ring bow whereas the other one carries a tooth likely to be caused to hook itself thereonto.
It is obvious that this complex mechanical structure which interconnects both monostable relay devices in order that the arrangement may operate as a bistable relay results in considerable inconveniences such as those of a high cost price and of reduced reliability and operating speed.